The present invention relates generally to tape recording and reproducing apparatus, and in particular to a pulse-operated mechanism for tape recorders. The invention is particularly suitable for use in battery-powered portable cassette tape recorders.
Mode switching mechanisms that are currently employed in tape recorders are broadly classified into mechanically an electrically operated types. Since the latter type permits selection of a desired mode in response to a featherly touch on the associated key or switch, it has gained wide popularity among users. However, the conventional electrically operated tape control mechanism employs a plurality of solenoids which are associated with different operating keys. This requires a substantial amount of power for operating various mechanical elements particularly because the circuitry is designed so that the solenoids remain energized during the time the recorder is being operated. Although this continuous power operation may find use in applications where the power is supplied from an external a.c. source, application to battery powered portable tape recorders is not possible due to excessive power consumption. Furthermore, use of a plurality of solenoids increases both size and manufacturing cost of the recorder.
Attempts have recently been made to reduce the amount of power consumption. One such method involves operating a solenoid or solenoids for a brief period during mode switching and locking the mechanism after it has been switched to the desired mode. Such method, however, makes use of pressure engaging action of a pinch roller, so that the operating solenoid has to bear a large amount of loading and consequently the amount of power consumption is still not satisfactory level for portable tape recorders. Another approach involves the use of an additional motor coupled with a plurality of solenoids which are responsive to input pulses for driving the motor to provide various switching operations. Disadvantage of the latter method is the complexity of mechanism and a high manufacturing cost.